Display.withCrLf() is producing wrong line breaks on Windows

[Christopher-Hermann]

Replacing all line breaks on windows with CrLf using regex, which is much safer.

Fixes #1557

[Christopher-Hermann]

I developed the fix on MacOS, so I had no change to test the fix. Would be nice if someone on windows can retest the fix.

[github-actions]

Test Results

   486 files  ±0     486 suites  ±0   9m 49s ⏱️ -2s
 4 308 tests +1   4 295 ✅ +1   13 💤 ±0  0 ❌ ±0 
16 413 runs  +1  16 305 ✅ +1  108 💤 ±0  0 ❌ ±0 

Results for commit fcaa4c2. ± Comparison against base commit d7febc4.

♻️ This comment has been updated with latest results.

[deepika-u]

@Christopher-Hermann
I tested this pr with below test case so that it covers all the cases from your fix(regex).

	@Test
	public void test_mixedLfAndCrfl() {
		//Use text control for testing since Display.withCrLf() is package private
		Text text = new Text(shell, SWT.None);

		//text.setText("First Line \n second line \r\n third line");
                //text.setText("\r First \r\r Line \n second \n\n line \r\n third \r\n\r\n line \r");
		text.setText("\n First \r\r Line \n second \n\n line \r\n third \r\n\r\n line \n");
		assertEquals("\r\n First \r\n\r\n Line \r\n second \r\n\r\n line \r\n third \r\n\r\n line \r\n", text.getText());
	}

Your fix works like charm.
It is clean, simple and straight forward. A go for the fix from my side.

Tested on below environment:
Eclipse SDK
Version: 2025-03 (4.35)
Build id: I20250107-1800
OS: Windows 11, v.10.0, x86_64 / win32
Java vendor: Eclipse Adoptium
Java runtime version: 23.0.1+11
Java version: 23.0.1

[DenisUngemach]

I have tested the PR on a Text Control on windows, it works.

One thing i want to mention. In this change a single \r will be replaced with a \r\n.
So we have this in the Text widget:

Before:
\r was shown as space
With PR:
\r is replaced with \r\n and shown as new line.

This is a change in the behavior.

Here are the uses:
\n (Line Feed):
on Unix systems
\r\n (Carriage Return + Line Feed):
on Windows-systems
\r (Carriage Return):
was used as new line on old macOS-versions (before OS X)

Please decide which behavior you wish. In my opinion both is fine and this is not that relevant.

[Christopher-Hermann]

Before: \r was shown as space With PR: \r is replaced with \r\n and shown as new line.

Good point. Since \r was used for new lines in older versions of macOS, I believe the new behavior is correct. It's likely that the old behavior was incorrect anyway. However, changing the behavior is of course never a good idea.

Any other opinions on that?

[BeckerWdf]

in older versions of macOS

how old are these "older versions" of macOS?

[BeckerWdf]

before OS X

Ah I see: "before OS X". This long time ago. I think we can merge this PR as it is.

[jukzi]

org.eclipse.swt.widgets.Display.withCrLf("\n ".repeat(100_000_000)); seems to be twice as slow now (#1718), can you please fix?